1. Technical Field
Various embodiments relate to a semiconductor design technology, and more particularly, to a semiconductor memory device and a data storage device including the same.
2. Related Art
Semiconductor memory devices are generally classified into volatile memory devices and nonvolatile memory devices. While a volatile memory device may lose stored data when power is turned off, a nonvolatile memory device may retain stored data even when not powered. The memory devices may include various types of memory cells.
The volatile memory devices may be classified into a static random access memory device (SRAM) and a dynamic random access memory device (DRAM), according to the types of memory cells. The nonvolatile memory devices may be classified into a flash memory device, a ferroelectric RAM (FRAM) using ferroelectric capacitors, a magnetic RAM (MRAM) using a tunneling magneto-resistive (TMR) layer, a phase change memory device (PCRAM) using a chalcogenide alloy, and a resistive memory device (ReRAM) using a transition metal oxide, according to the structures of memory cells.
A semiconductor memory device may be controlled by a chip select signal provided from an external device (e.g., a controller). For example, when the chip select signal is activated, the semiconductor memory device may operate in a normal mode in which it may perform a read operation, a write (or a program) operation or an erase operation. On the other hand, when the chip select signal is deactivated, the semiconductor memory device may operate in a power-saving mode in which it does not perform an internal operation. The semiconductor memory device is to be designed to stably enter an operation mode corresponding to the chip select signal.